The present invention relates to ophthalmic pharmaceutical compositions and methods of making and using such compositions. The present invention also relates to enhanced delivery of ophthalmic pharmaceutical ingredients in ophthalmic compositions and methods of making and using such compositions. Some embodiments of the present invention relate to compositions and methods for reducing, ameliorating, treating, or preventing discomfort of dry eye condition.
Prior-art ophthalmic compositions often suffer from inefficient delivery of beneficial ingredients, including ophthalmic pharmaceutical active ingredients, to the eye. Disadvantages of these compositions include short duration of the composition on the eye due to continuous drainage or evaporation.
Dry eye, also known as keratoconjunctivitis sicca or dyslacrima, is a common ophthalmological disorder affecting millions of people. A patient with dry eye may experience burning, a feeling of dryness, and persistent irritation. In severe cases, dry eye can seriously impair a person's vision and hence handicap the sufferer in activities such as driving. Certain diseases such as Sjogren's disease manifest dry eye symptoms. Also, as people age, the lacrimal glands in the eye may produce less moisture, resulting in eyes that become dry, inflamed, itchy, and gritty.
Although it appears that dry eye may result from a variety of unrelated pathogenic causes, all presentations of the condition share a common feature, namely the breakdown of the precorneal tear film, which breakdown commonly results in dehydration of the exposed outer ocular surface and hence the symptoms described above.
A number of approaches exist for the treatment of dry eye. One common approach has been to supplement the ocular tear film using artificial tears instilled throughout the day. Examples of the tear substitute approach include the use of buffered, isotonic saline solutions and aqueous solutions containing water-soluble polymers that render the solutions more viscous and thus less easily shed by the eye by the washing action of the tear fluid. See, for example, U.S. Pat. No. 5,209,927 to Gressel et al.; U.S. Pat. No. 5,294,607 to Glonek et al.; and U.S. Pat. No. 4,409,205 to Shively;
Although these approaches have met with some success in some cases, significant challenges in the treatment of dry eye nevertheless remain. Problems include the fact that the use of tear substitutes, while temporarily effective, generally requires repeated application over the course of a patient's waking hours, not uncommonly ten or more times over the course of a day to keep the ocular surface lubricated or moist. Such an approach is inconvenient to a patient. Although increasing the viscosity of the dry-eye product may extend the product's duration in the eye, increase in viscosity is effective at extending duration only to a limited extent. Viscous ophthalmic drops are sometimes undesirable because they feel sticky in the eye. Further, increases in the duration of the product would be highly desirable.
Therefore, in view of the shortcomings of prior-art compositions, there is a continued need to provide improved ophthalmic pharmaceutical compositions for enhanced delivery of active pharmaceutical ingredients (“APIs”) to the eye. For example, it is desirable to provide improved ophthalmic compositions for the reduction, amelioration, treatment, or prevention of the discomfort resulting from the dry eye condition. It is also desirable to provide such compositions that are gentle to the ocular surface.